Preheat oven to 180C/350F/Gas 4. Grease and line three 20cm/8in cake tins.
Sift the flour, caster sugar, ground cinnamon and bicarbonate of soda together in a bowl.
Stir in the eggs, sunflower oil, nuts, fruit and orange zest until well combined.
Divide the cake batter among the three cake tins and bake in the oven for 30-35 minutes, or until risen and golden-brown.
Remove from the oven and set aside to cool for 10 minutes. Run a round-bladed knife around the inside edge of the tins to loosen the cakes. Remove the cakes from their tins and transfer to a wire rack to cool completely.
Meanwhile, for the cream cheese icing, blend the cheese and butter together with an electric whisk until thick and creamy. Add the orange zest and sift in the icing sugar. Stir gently until well combined, then chill in the fridge until needed.
Once the cakes are cool, spread cream cheese icing on top of each cake. Stack the cakes to make one three-tiered cake.